Sludge separator with automatic control



u y-4 1969 H. HEMFORT 3,454,216

SLUDGE SEPARATOR WITH AUTOMATIC CONTROL Filed July 24, 1967 FIG. I.

FIG. 2.

INVENTOR HEINRICH HEMFO'RT United States Patent 3,454,216 SLUDGE SEPARATOR WITH AUTOMATIC CONTROL Heinrich Hemfort, Oelde im Westphalia, Germany, as-

signor to Westfalia Separator AG, Oelde Westphalia,

Germany Filed July 24, 1967, Ser. No. 655,383 Claims priority, application Germany, Aug. 11, 1966, W 42,193, Patent 1,173,030 Int. Cl. B04b 11/04 US. Cl. 23320 7 Claims ABSTRACT OF THE DISCLOSURE Sludge separation centrifuge having sludge removal means associated with the drum thereof, having actuating means connected thereto wherein said actuating means is itself actuated by an impeller within said centrifuge driven by liquid separated from the sludge.

Centrifuges which separate sludge or other solids from liquid associated therewith are known. In some of the newer types aof centrifuges which are known for this purpose, discharge openings in the centrifuge wall are provided which are opened by an axially displaceable sliding piston when the sludge accumulation reaches a predetermined level, whereby sludge is discharged therethrough. Upon discharge of all or a part of the sludge, the discharge openings are closed by the sliding piston and sludge is again built up within the centrifuge sludge chamber. The lighter liquid passes through a disc set and is removed from a chamber adjacent the centrifuge axis.

It is known to activate the sliding piston for discharging the solids through an external control fluid which itself is controlled, e.g., by means of a solenoid or similar valve. It is also known to provide devices which give off a signal or a control pulse when a component of material being centrifuged which is connected in the sludge chamber of a. centrifuge bowl has reached a predetermined level. It is further known to provide devices for the automatic control of sludge separators in which a detector liquid is introduced into a central chamber through a peeling disc which, upon dipping into the liquid which moves inward as the sludge compartment becomes filled, brings about the response of a pressure switch. These devices have the disadvantage that, as a result of the small diameter of the peeling disc, the pressure produced is only relatively slight. Furthermore, these devices require tight connections to the pressure switch, since leaks will jeopardize the proper response of the switch. The greatest disadvantage is, however, that during normal operation, when the peeling disc for the feeding of the detector liquid is not dipped into the rotating liquid, gases and vapors can escape from the inlet compartment of the bowl through said peeling channels. In the case of a separation of liquids which contain gas, for instance, beer, the inlet chamber of the bowl must, however, be under elevated pressure so that the carbon dioxide does not escape from the beer.

It is therefore an object of this invention to provide an improved centrifuge control system.

It is another object of this invention to provide an improved system for the actuation of sludge discharge means in a centrifuge.

Other and additional objects of this invention will become apparent from a consideration of this entire specification, including the drawing and claims hereof.

In accord with and fulfilling these objects, one aspect of this invention resides in the provision, in a centrifuge, of an impeller capable of being driven by the lighter 3,454,216 Patented July 8, 1969 liquid being separated from the sludge. The impeller is arranged in the central chamber and is stationary during the normal operation of the centrifuge, said impeller carrying out a rotary movement when it dips into the liquid which moves radially inward upon the filling of the sludge chamber and rotates with the bowl, thereby giving off an optical or acoustic signal and/or imparting a starting impulse to the sludge-removal process.

The impeller can be arranged in a separate chamber, or else in the central inlet chamber for the liquid to be centrifuged. In the latter case, the free liquid level of the material to be centrifuged moves radially inward when its entrance into the chamber outside the set of discs is impeded by solids.

As impulse transmitter, there can be used a switch which may be arranged either inside or outside the bowl. It may be a mechanically, inductively or capacitively actuated switch; in the two last-mentioned cases, an inductive or capacitive field being affected by the rotation of the impeller. In general, it will then be necessary to limit the rotation motion by a stopping or opposing force. Furthermore, means can be provided which turn the impeller back into its initial position when the liquid in the central chamber retreats.

When cams are used for the mechanical actuation of contacts, a limiting of the rotary movement and a resetting of the impeller are not necessary.

Since the sludge-removal process is commenced by actuation of a valve in the feedline of a control fluid, for instance, compressed air or control liquid, the impulse transmitter actuated by the impeller can directly close or open the circuit to an electromagnetic valve in such feedline and, upon the retreating of the liquid level, switch it back again.

Aside from the fact that the impeller in accordance with the invention, being a mechanical part, increases the dependability of response and can be made relatively strong, the device in accordance with the invention eliminates all the aforementioned disadvantages of the previously known arrangements.

One embodiment of the invention is shown by way of example in the drawing, in which:

FIG. 1 shows the entire bowl of a sludge separator, partially in section, and

FIG. 2 is an enlarged showing of the central part, with the impeller.

Referring now to the drawing, 1 is the bottom of the bowl and 2 the top of the bowl, these parts being held together by a closure ring 3. In the bottom 1 of the bowl, there are provided ejection openings 4 for the solids which, during operation, can be opened by an axially displaceable piston valve 5 for the ejection of the solids. The liquid to be centrifuged is introduced through a conduit 6 and passes through a stationary inlet pipe 7 and its extension 8 into a central inlet compartment 9 of the bowl. The liquid from which solids have been removed passes through bore holes 10 into a peeling chamber 11 and is discharged under pressure by means of a peeling disc 12 through a conduit 13. The peeling disc '12 which dips into the rotating liquid forms a liquid seal for any gases possibly present in the inlet chamber of the bowl. A small part of the clarified liquid is conducted by at least one of the peeling channels 14 (FIG. 2) through a channel 15 into a chamber 16 from which it passes through channels 17 into the sludge chamber 18 of the bowl.

On the stationary inlet pipe 7, there is rotatably supported an impeller 19 which is rigidly fastened by ribs 20 to a shaft 21 extending out of the bowl. Over the end of this shaft 21, there is placed a pinion 22 which, upon rotation of the impeller 19, displaces a rack 23 which actuates a switch 24 which, in the embodiment shown by way of example, places a solenoid valve 25, in the feedline 26 for the control fluid, under voltage.

Instead of a pinion 22, a disc to which a bush rod 23 is eccentrically fastened can also be placed on the shaft 21. The switch 24 is advisedly a push-button switch of the same type as a bell button which, when depressed, closes contacts and then, when released, opens them again. When such a switch is used, the impeller is turned back by the spring tension of the switch button into its original position when the liquid level in the chamber 12 moves back during the ejection of sludge and no force is exerted any longer on the impeller.

The invention is not limited to the embodiment shown by way of example but can be modified within the scope of the possibilities indicated above.

What is claimed is:

1. In a centrifuge having an inlet, a sludge chamber, a disk set, an outlet from said disk set for clarified effiuent directed toward the axis of said centrifuge, and sludge discharge means in said chamber; the improvement which comprises a rotatable impeller operatively associated with said outlet, communication means between said sludge chamber and said impeller, means for freely rotatably mounting said impeller, and external control means operatively associated with said rotatable impeller and operable to control said sludge discharge means; whereby upon said chamber filling with sludge, liquid from said chamber activates said impeller, causes such to rotate and said impeller rotation activating said external control means.

2. The improved centrifuge claimed in claim '1, wherein said impeller is located in a central chamber in said centrifuge and is driven by liquid moving radially toward the centrifuge axis.

3. The improved centrifuge claimed in claim 1, wherein said impeller rotation generates an electrical impulse.

4. The improved centrifuge claimed in claim 1, wherein said impeller is located in an inlet chamber of said centrifuge.

5. The improved centrifuge claimed in claim 1, wherein the rotary movement of said impeller is limited.

6. The improved centrifuge claimed in claim 5, wherein said impeller is reset after said sludge is discharged.

7. The improved centrifuge claimed in claim 1, wherein said external control means includes a solenoid valve.

References Cited UNITED STATES PATENTS 3,167,509 1/1965 Steinacker REUBEN FRIEDMAN, Primary Examiner.

J. L. DE CESARE, Assistant Examiner.

U.S. Cl. X.R. 210-369 

